// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <memory>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/macros.h"
#include "base/strings/stringprintf.h"
#include "media/base/audio_bus.h"
#include "media/base/audio_pull_fifo.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace media {

// Block diagram of a possible real-world usage:
//
//       | Producer | ----> | AudioPullFifo | ----> | Consumer |
//                    push                    pull
//          2048      ---->       (2048)      ---->     ~512

// Number of channels in each audio bus.
static int kChannels = 2;

// Max number of audio framed the FIFO can contain.
static const int kMaxFramesInFifo = 2048;

class AudioPullFifoTest
    : public testing::TestWithParam<int> {
public:
    AudioPullFifoTest()
        : pull_fifo_(kChannels,
            kMaxFramesInFifo,
            base::Bind(&AudioPullFifoTest::ProvideInput,
                base::Unretained(this)))
        , audio_bus_(AudioBus::Create(kChannels, kMaxFramesInFifo))
        , fill_value_(0)
        , last_frame_delay_(-1)
    {
        EXPECT_EQ(kMaxFramesInFifo, pull_fifo_.SizeInFrames());
    }
    virtual ~AudioPullFifoTest() { }

    void VerifyValue(const float data[], int size, float start_value)
    {
        float value = start_value;
        for (int i = 0; i < size; ++i) {
            ASSERT_FLOAT_EQ(value++, data[i]) << "i=" << i;
        }
    }

    // Consume data using different sizes, acquire audio frames from the FIFO
    // and verify that the retrieved values matches the values written by the
    // producer.
    void ConsumeTest(int frames_to_consume)
    {
        int start_value = 0;
        SCOPED_TRACE(base::StringPrintf("Checking frames_to_consume %d",
            frames_to_consume));
        pull_fifo_.Consume(audio_bus_.get(), frames_to_consume);
        for (int j = 0; j < kChannels; ++j) {
            VerifyValue(audio_bus_->channel(j), frames_to_consume, start_value);
        }
        start_value += frames_to_consume;
        EXPECT_LT(last_frame_delay_, audio_bus_->frames());
    }

    // AudioPullFifo::ReadCB implementation where we increase a value for each
    // audio frame that we provide. Note that all channels are given the same
    // value to simplify the verification.
    virtual void ProvideInput(int frame_delay, AudioBus* audio_bus)
    {
        ASSERT_GT(frame_delay, last_frame_delay_);
        last_frame_delay_ = frame_delay;

        EXPECT_EQ(audio_bus->channels(), audio_bus_->channels());
        EXPECT_EQ(audio_bus->frames(), kMaxFramesInFifo);
        for (int i = 0; i < audio_bus->frames(); ++i) {
            for (int j = 0; j < audio_bus->channels(); ++j) {
                // Store same value in all channels.
                audio_bus->channel(j)[i] = fill_value_;
            }
            fill_value_++;
        }
    }

protected:
    AudioPullFifo pull_fifo_;
    std::unique_ptr<AudioBus> audio_bus_;
    int fill_value_;
    int last_frame_delay_;

    DISALLOW_COPY_AND_ASSIGN(AudioPullFifoTest);
};

TEST_P(AudioPullFifoTest, Consume)
{
    ConsumeTest(GetParam());
}

// Test common |frames_to_consume| values which will be used as input
// parameter to AudioPullFifo::Consume() when the consumer asks for data.
INSTANTIATE_TEST_CASE_P(
    AudioPullFifoTest, AudioPullFifoTest,
    testing::Values(544, 512, 512, 512, 512, 2048, 544, 441, 440, 433, 500));

} // namespace media
